Diagnosis

Since the signs and symptoms of diabetes insipidus can be caused by other conditions, your doctor will perform a number of tests. If your doctor determines you have diabetes insipidus, he or she will need to determine which type of diabetes insipidus you have, because the treatment is different for each form of the disease.

Some of the tests doctors commonly use to diagnose and determine the type of diabetes insipidus and in some cases, its cause, include:

Water deprivation test. This test confirms the diagnosis and helps determine the cause of diabetes insipidus. Under medical supervision, you'll be asked to stop drinking fluids for a time so that your doctor can measure changes in your body weight, urine output and the concentration of your urine and blood when fluids are withheld.

Your doctor may also measure blood levels of ADH or administer synthetic ADH during this test. The water deprivation test is performed under close supervision in children and pregnant women to make sure no more than 5 percent of body weight is lost during the test.

Urinalysis. Urinalysis is the physical and chemical examination of urine. If your urine is less concentrated — meaning the amount of water is high relative to other excreted substances — it could be due to diabetes insipidus.

Magnetic resonance imaging (MRI). An MRI of the head is a noninvasive procedure that uses a powerful magnetic field and radio waves to construct detailed pictures of brain tissues. Your doctor may want to perform an MRI to look for abnormalities in or near the pituitary gland.

Genetic screening

If your doctor suspects an inherited form of diabetes insipidus, he or she will look at your family history of polyuria and may suggest genetic screening.

Treatment

Treatment of diabetes insipidus depends on what form of the condition you have. Treatment options for the most common types of diabetes insipidus include:

Central diabetes insipidus. Because the cause of this form of diabetes insipidus is a lack of anti-diuretic hormone (ADH), treatment is usually with a synthetic hormone called desmopressin. You can take desmopressin as a nasal spray, as oral tablets or by injection.

The synthetic hormone will eliminate the increase in urination. For most people with this form of the condition, desmopressin is safe and effective. If the condition is caused by an abnormality in the pituitary gland or hypothalamus (such as a tumor), your doctor will first treat the abnormality.

Desmopressin should be considered a medication you take as needed. This is because in most people, the deficiency of ADH is not complete, and the amount made by the body can vary day to day.

Taking more desmopressin than needed can result in too much water retention and low sodium levels in the blood. Symptoms of low sodium include lethargy, headache, nausea and, in severe cases, seizures.

In mild cases of central diabetes insipidus, you may need only to increase your water intake.

Nephrogenic diabetes insipidus. This condition is the result of your kidneys not properly responding to ADH, so desmopressin is not a treatment option. Instead, your doctor may prescribe a low-salt diet to help reduce the amount of urine your kidneys make. You'll also need to drink enough water to avoid dehydration.

The drug hydrochlorothiazide, used alone or with other medications, may improve symptoms. Although hydrochlorothiazide is a diuretic (usually used to increase urine output), in some cases it can reduce urine output for people with nephrogenic diabetes insipidus.

If symptoms from nephrogenic diabetes insipidus are due to medications you're taking, stopping these medicines may help; however, don't stop taking any medication without first talking to your doctor.

Gestational diabetes insipidus. Treatment for most cases of gestational diabetes insipidus is with the synthetic hormone desmopressin. In rare cases, this form of the condition is caused by an abnormality in the thirst mechanism. In these rare cases, doctors don't prescribe desmopressin.

Primary polydipsia. There is no specific treatment for this form of diabetes insipidus, other than decreasing the amount of fluid intake. However, if the condition is caused by mental illness, treating the mental illness may relieve the symptoms.

Lifestyle and home remedies

If you have diabetes insipidus:

Prevent dehydration. As long as you take your medication and have access to water when the medication's effects wear off, you'll prevent serious problems. Plan ahead by carrying water with you wherever you go, and keep a supply of medication in your travel bag, at work or at school.

Wear a medical alert bracelet or carry a medical alert card in your wallet. If you have a medical emergency, a health care professional will recognize immediately your need for special treatment.

Preparing for your appointment

You're likely to start by seeing your primary care doctor. However, in some cases when you call to set up an appointment you may be referred to a specialist called an endocrinologist.

Here's some information to help you get ready for your appointment.

What you can do

Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance. Your doctor may ask you to stop drinking water the night before — do so only if your doctor asks you to.

Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment. Be prepared to answer specific questions about how often you urinate and how much water you drink each day.

Write down key personal information, including any major stresses or recent life changes.

Make a list of your key medical information, including recent surgical procedures, the names of all medications you're taking and any other conditions for which you've recently been treated. Your doctor will also want to know about any recent injuries to your head.

Take a family member or friend along, if possible. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.

I have these other health conditions. How can I best manage these conditions together?

Are there any dietary restrictions I need to follow?

Are there brochures or other printed material I can take home or websites you recommend?

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

When did you begin experiencing symptoms?

How much more are you urinating than usual?

How much water do you drink each day?

Do you get up at night to urinate and drink water?

Are you pregnant?

Are you being treated or have you recently been treated for other medical conditions?

Have you had any recent head injuries or have you had neurosurgery?

Has anyone in your family been diagnosed with diabetes insipidus?

Does anything seem to improve your symptoms?

What, if anything, appears to worsen your symptoms?

What you can do in the meantime

While you're waiting for your appointment, drink until your thirst is relieved, as often as necessary. Avoid activities that might cause dehydration, such as physical exertion or spending time in the heat.

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